Combustion apparatus



GOMBUSTION APPARATUS Filed. March 21, 1942 2 Sheets-Sheet l WITNESSES:

ATTORNEY Douma' J. Mossunm Oct- 23, 1945- u D. .LMo'ssHRT 2,387,600

COMBUSTION APPARATUS Filed March 2l, 1942 2 Sheets-Sheet 2 mvENToRDoNnLD J. MossHnnT.

BY OWPDLM.;

I ArroRNEY Patented Oct. 23, 1945 S PATENT N y.artistaN `OFFIGIECOMBUSTION APPARATUS Donald J. Mosshart, Ardmore, Pa., assignor to) uWestinghouse Electric Corporation, East Pittsburgh, Pa., a corporationof Pennsylvania Application March 21, 1942, Serial No. 435,647 claims.A,(cl. 11o-3s) `'I'his invention relates to furnaces, more pareticularlyto those `of the stoker-red type, and has for an object toprovide novel and improved apparatus of this character.

A further object of theinvention is to provide a ASpreader-fed Stokerwherein' fuel is deposited on a central portion of the fuel-supportinggrate surface, where itis partially coked and ignited and then `is fedlaterally in opposite directions over side rportions of the gratesurface where it is consumed. M 4

, Another object ofthe invention is to provide a progressive-feed gratestructure wherein a plurality of bars ofinverted-V configuration extendtransversely of the Stoker inside by side relation, a number'of thefbarsbeing stationary, and the remainderbeing reciprocatory and interspersedamong the stationary bars.' y

4 Yet another object of the invention'is the provision, in aspreaderefed'progressive feed stocker,

or pressure responsive means for maintaining a predetermined ratiobetween rate of feed of fuel tothe grateand rate of flow of air to thefuelfed portion of the grate.

. These and other objects are 4effected by the invention as will beapparent from the following description and claims taken in connectionwith the accompanying drawings, forming a part of .this application, inwhich:

g Fig. l is a' longitudinal sectional View taken along the line I-I ofFig. 3, looking in the direction of the arrows; t

Fig.' 2 is a horizontal sectional view, taken along the line II-II ofFig. 1, looking in the direction of the arrows;

Fig. 3` is a transverse sectional view taken along the line III--III ofFig. 2, looking in the direction ofthe arrows; 'A ili'ig.' 4 is a viewin perspective of one ofthe movinggrate bars;'and, 1 l Fig.`5 is a sideelevational view of one of the stationary grate bars. Referring now tothe drawings more in detail, there is shown, at l0, a furnace comprisingfront andire'ar walls Il and l2, respectively, and side wallsV I3.Positioned within the lower portion of the furnace' l0 is a s'toker I4,comprised'by a row of :alternate moving and stationary grate bars I5 andIE, respectively.

^ A plurality of lwall members 20, together with structural steelmembers 2| and 22, carriedv thereby, extend lfrom front to rear ofthefur.- nace and constitute supports for theY row of grate bars.

`The moving bars I5` are provided at their lower sideswith supportingsurfaces adapted to slidably engage the upper surfaces of the supportingmem-` bers 2| and 22, the stationary bars I6 also having flat supportingsurfaces at their under sides for similar engagement with the supportingmembers.

In order to impart transverse reciprocatory motion to the moving barsl5, the latter are each provided with a depending yoke member 24 adaptedto receive a pin 25projecting upwardly from a drive shaft 26, the latterextending longitudinally of the row of grate bars from front to rear ofthe furnace, the forward end of the shaft 26 projecting forwardlythrough the front wall Il of the furnace and being equipped withsuitable linkage 21 through which oscillatory motion may be impartedthereto by suitable means,-

not illustrated.

In order to prevent any transverse reciprocatory motion of thestationary bars I6, the latter are provided with a plurality ofdepending lugs 29 and 30 adapted to engage laterally against the sidesof the top flanges of the supporting members 2l and 22.

A desirable feature of the grate bar construction just described is thatboth types of bars, that is, reciprocatory and stationary, may 'beremoved and replaced by a simple vertical movement and without thedisengagement of any fastening means, such as bolts, clamps, etc.

In 'the construction herein illustrated, both moving and stationarybarsare shown as beineJr ofY composite constructionfeach -bar comprisinga pair of identical bars joined together rigidly by suitable means,'suchas the bolts 32. to provide forthe desired ow of air between theadjacent grate bars, the side surfaces of the barsv It will be apparentfrom consideration of Fig. 3

that the supporting members 20, 2| and 22 serve the added function ofdividing the space beneath the row of grate bars into a central plenumchamberv35 and a pair of side plenum chambers `36. A plurality of ducts38, 39 and 40 serve to conduct air under `pressure to the plenumchambers from a suitable source, for example, the blower 4l.

In order to control the supply of air to thecentrai-plenum chamber 35,there is provided in the duct 38 a metering orice 42 followed by adamper 43. kPressure-responsive apparatus, at 44, provides for variation`in the flow of air ,to the chamber l35 In order in direct proportion tovariations in the quantity of fuel fed to the grate, as will be morefully explained hereinafter. Coal from the hopper body 45 is fed, bymeans of a plurality of rams 46, through the opening 41 in the furnacefront wall Il, where the spreader 48 sprinkles the coal over a centralportion of the great-surface which is in communication with the plenum'chamber 35, .this central portion extending from front -to rear of thefurnace.

A variable speed motor` 50, driving through belts and 52, operates boththe ram 46 and the spreader 48.

In order that the supply of air tothe central. plenum chamber 35 may bevaried' inv direct pro.-Y portion to changes in rate of feedI of fuel tothat portion of the grate surface overlying the plenum chamber 35, themotor 50 is directly connected to a tachometer blower 52a which suppliesair under pressure to a bellows 53, the latter being connected throughthe compression spring 54to one end of the lever 55, pivotally mountedintermediate its ends on a fixed support, at 56. The compression spring54, whose tension may be adjusted by the screw 51, urges the right-handend of the lever 55 upwardly with respect to the bellows 53. Theleft-hand end of the lever 55. is connected through the rod 58' to apair of spaced' bellows 60 and 6|, the former being in communi cationwith the upstream side of the metering orifice 42 and the latter beingin communication with the downstream side thereof. The lever 55 is alsoconnected through the stem 62 with the valve 63 controlling flow ofpressure medium through the conduit 64, the latter being incommunication with the expansible chamber 65, en closed in part bythemovable piston or abutment 61, which is connected by the rod 681 withthe bell crank 69', iixedly secured to the damper 43 in the passage 38.A compression spring TI exerts force in the piston orl abutmentinopposition to the force of fluid pressure acting thereon.

In operation, it will be apparent that any increase in the rate of feedof fuel to the grate surface will result in increased speedV ofthetachometer blower 52a and increased` pressure within the bellows 53.This in turn will produce upward movement of the right-hand end of thelever 55 and opening of the valve 63. As a result, the pressure withinthe chamber 65 will be increased, causing downward movement ofthe piston61 and rod 68 carried thereby, thereby further opening the damper 43,resulting in increased flow of air to the central plenum chamber 35. Asthe` chamber opens, the differential pressure across the meteringorifice 42 decreases, resulting in upward force and movement applied tothe left-hand end of the lever 55. The lever will moveuntil equilibriumof forces acting thereon is restored with thev valve 63 adjusted for theincreased fuel feed rate. If the rate of fuel feed is decreased, thecontrary operation takes place. By adjusting the spring 54, the relationof fuel feed' rate to air flow rate to the central duct 38 and plenumchamber 35 maybe varied.

- fuel bed adapted to be fed laterally-of the stoker as; thel result ofreciprocation of the movable grate bars l5, the fuel being consumedV asit passes over the side portions of the fuel supporting grate surfaceoverlying the side plenum chambers 36. Ash and unconsumed refuse leavingthe lower ends of the grate bars may be received upon ash dump plates'l0 and periodically discharged into the ash pits 'll provided at eachside of the furnace.

While in the embodiment herein illustrated, thegfurnace has been shownas .containing only onestoker, it will be apparent that; the inventionis not limited to this arrangement but may include the provision of twoor more stokers disposed in side by side relation and extending fromfront to rear of the furnace, together with a corresponding number offuel feeding and spreading devices associated therewith.

While-the invention has been shown in but one form, it Vwill be obviousto those skilled in the art that itis notso limited, but is susceptibleof variouschanges and modifications without departing from the spiritthereof, and it is desired, therefore, thatl only such limitations shallbe placed` thereupon as are specifically set forthin the-appendedclaims.

What is claimed is: K Y

1. A furnace having front', rear and sidewalls; a stoker disposed in thelower portion of saidV furnace and comprising a row oftransversely-disposed grate bars, which row extends from front to rearof the furnace and comprises a plurality of reciprocatory barsinterspersed among a plurality of stationary bars and provides afuel`supporting surface of inverted-V shape in transverse section havinga central portion adjacent the apex'of.` the inverted-V flanked by twoside portions at the-legs of the inverted-V; means forfeeding coalthrough the furnace front wall a material distance above thefuel-supporting surface and spreading it-over the central portionthereof from front to rear of the furnace; and means for impartingtransverse reciprocatory' motion to the reciprocatory bars to feed thecoal from said'central portion latierally in opposite directions overthe si'de portions.

2'. A furnace having front, rear and si'de Walls; a stoker disposed inthe lower portion ofs'aid'furnace and comprising a row oftransversely-disposed grate bars, which row extends from front to` rearofthe furnace and comprises a numbery of reciprocatory barsinterspersedt among a number of stationary bars, saidV row of" barsproviding a fuel-supporting surfaceV of inverted-V shape in transversesectionv having a central portion adjacent the apex of the inverted-Vandsside p0r= tions at the legs of the" inverted-V,` means'for feedingcoal through the furnace front wall and spreading it over said centralportion of the fuelf supporting surfacefrom frontl t 0V rear 'off thefurnace for partial coking and ignition' thereon, a first means carriedby each reciprocatory bar, and second means extending longitudinally-ofthe row of grate bars and engaging: said, first means, said first andsecond meansg being adaptedto impart transverse reciprocatory motion tothe reciprocatory bars to feed the partially coked and ignited coal fromthe central portion laterally over they side portions for consumption atsaidf side portions.

3. Structure as specified in claim 2, wherein the row oftransversely-disposed grate bars comprises alternate reciprocatory andstationary bars:

4. Apparatus of the character described! comprising a furnace; grate'structure withintheffurgnace; fuel-feeding mechanismA of the sprinkler'or spreader type for sprayingfuel freely'overa ceri--v tral portion ofthe grate, which portion extends' from front to rear of the' furnace andis;l spaced from the side walls thereof, whereby a substantial portionof combustion takes place while the fuel is in suspension; and means forimparting movement to the grate structure to feed the fuel transverselyof the furnace along the grate from the central portion to the sides ofthe furnace.

5. Apparatus of the character described comprising a furnace; gratestructure within the furnace providing a fuel-supporting` surface ofinverted-V shape in transverse section having a central portion adjacentthe apex of the inverted- V anked by two side portions of the legs ofthe inverted-V; fuel-feeding mechanism of the sprinkler or spreader typefor spraying fuel freely over said central portion of the grate, whichportion extends from front to rearl of the furnace, whereby asubstantial portion of combustion takes place while the fuel is insuspension; and means for imparting movement to the grate structure forfeeding the fuel from said central portion laterally 10 in oppositedirections over said side portions.

DONALD J. MossHART'. p

CERI'IFICA'I'E.` 'OF CORRECTION.

Patent No, 2,587,600. october 25. 1915.

DONALD J. MossHART.

It is hereby certified thatlerror .appears in the printed specificationof the above numbered patent requiring correction as "follows: Page l,first column, line 2l, for 'or pressure read --oi pressure page V2,firstl column, line Y, forY ugreatu readl --grate--g and that the saidLetters Patent' should be read with this correction therein that thesame may' conform t0` the record of the oase in the Patent Office.

Signed and sealed this 22nd day of January, A. D. 19h61.

Leslie Frazer `(Seal) First Assistant Commissioner of Patents.

